ds3102 Maxim Integrated Products, Inc., ds3102 Datasheet - Page 15

• Manufacturer Part Number: ds3102
• Description: Stratum 3 Timing Card Ic With Synchronous Ethernet Support
• Manufacturer: Maxim Integrated Products, Inc.

Table 6-3. Global Pin Descriptions
Table 6-4. SPI Bus Mode Pin Descriptions
See Section
Rev: 012108
____________________________________________________________________________________________ DS3102
PIN NAME
PIN NAME
SONSDH/
INTREQ/
SRCSW
SRFAIL
GPIO4
CPHA
LOCK
CPOL
TEST
SCLK
WDT
SDO
LOS
RST
SDI
CS
7.10
(1)
(1)
for functional description and Section
TYPE
TYPE
I/O
I
I
I
I/O
O
I
I
O
O
O
PU
PD
PD
PU
PD
I
I
I
PD
3
(2)
(2)
SRFAIL Status. When MCR10:SRFPIN = 1, this pin follows the state of the SRFAIL latched
status bit in the
current reference. When MCR10:SRFPIN = 0, SRFAIL is disabled (low).
Reset (Active Low). When this global asynchronous reset is pulled low, all internal circuitry is
reset to default values. The device is held in reset as long as RST is low. RST should be held
low for at least two REFCLK cycles after the external oscillator has stabilized and is providing
valid clock signals.
Source Switching. Fast source-switching control input. See Section 7.6.5. The value of this pin
is latched into MCR10:EXTSW when RST goes high. After RST goes high this pin can be used
to select between IC3/IC5 and IC4/IC6, if enabled.
Factory Test Mode Select. Wire this pin to V
Watchdog Timer Pin. Analog node for the REFCLK watchdog timer. Connect to a resistor (R)
to V
Section 7.3.
SONET/SDH Frequency Select Input/General-Purpose I/O 4. When RST goes high the state
of this pin sets the reset-default state of MCR3:SONSDH, MCR6:DIG1SS, and MCR6:DIG2SS.
After RST goes high this pin can be used as a general-purpose I/O pin. GPCR:GPIO4D
configures this pin as an input or an output. GPCR:GPIO4O specifies the output value.
GPSR:GPIO4 indicates the state of the pin.
Reset latched values:
T0 DPLL LOCK Status. When MCR1.LOCKPIN = 1, this pin indicates the lock state of the T0
DPLL. When MCR1.LOCKPIN = 0, LOCK is disabled (low).
Interrupt Request/Loss of Signal. Programmable (default: INTREQ). The INTCR:LOS bit
determines whether the pin indicates interrupt requests or loss of signal (i.e., loss of selected
reference).
INTCR:LOS = 0: INTREQ Mode. The behavior of this pin is configured in the
Polarity can be active high or active low. Drive action can be push-pull or open drain. The pin
can also be configured as a general-purpose output if the interrupt request function is not
needed.
Chip Select. This pin must be asserted (low) to read or write internal registers.
Serial Clock. SCLK is always driven by the SPI bus master.
Serial Data Input. The SPI bus master transmits data to the device on this pin.
Serial Data Output. The device transmits data to the SPI bus master on this pin.
Clock Phase. See
0 = Data is latched on the leading edge of the SCLK pulse.
1 = Data is latched on the trailing edge of the SCLK pulse.
Clock Polarity. See
0 = SCLK is normally low and pulses high during bus transactions.
1 = SCLK is normally high and pulses low during bus transactions.
DDIO
0 = SDH rates (N x 2.048MHz)
1 = SONET rates (N x 1.544MHz)
0 = Not locked
1 = Locked
INTCR:LOS = 1: LOS Mode. This pin indicates the real-time state of the selected
reference activity monitor (see Section 7.5.3). This function is most useful when external
switching mode (Section 7.6.5) is enabled (MCR10:EXTSW = 1).
and a capacitor (C) to ground. Suggested values are R = 20kΩ and C = 0.01μF. See
MSR2
10.4
Figure
Figure
register. This gives the system a very fast indication of the failure of the
for timing specifications.
7-5.
7-5.
PIN DESCRIPTION
PIN DESCRIPTION
SS
for normal operation.
INTCR
register.
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